220 Which one of the following statements is correct a Addin

2.20 Which one of the following statements is correct? (a) Adding 5% to 6% of moisture by weight increases the volume of dry sand from (b) The bulking of fine sand is more than (c) Volume of full saturated sand is equal to (d) All of the above 18% to 38% that of coarse sand that of dry sand.

Solution

Option d is correct.

Compared to its dry or completely saturated volume, moist fine aggregate tends to increase in volume on rehandling due to capillary effect. The capillary action between sand particles does not allow the particles to come closer to each other. This is called bulking of sand and the amount of bulking or increase in volume depends on the moisture content of the sand. In completely dry or wet state, there is no capillary action and hence, there will be no bulking when the sand is dry or completely saturated. For a moisture content of 5 to 8 per cent, the bulking can be as much as 20 to 40 per cent depending on the sand.